Device for dispensing a liquid in the form of drops

ABSTRACT

The device makes it possible to dispense predetermined metered quantities of liquid. It includes a sealing member that can take up a liquid release position, allowing liquid to flow out of the device, and a non-return position preventing liquid from flowing back into the device. The sealing member is provided with metering means for metering out the liquid to be dispensed.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of pending Internationalpatent application PCT/FR2009/000356 filed Mar. 27, 2009, whichdesignates the United States and claims priority from French patentapplications FR 0851994 filed Mar. 27, 2008 and FR 0805717 filed Oct.15, 2008, the content of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to the technical field of dispensingpredetermined metered quantities or “doses”. More precisely, but notexclusively, the present invention relates to dispensing ophthalmicliquid such as collyrium or eyewash in the form of drops.

BACKGROUND OF THE INVENTION

State-of-the art devices are already known that make it possible toimplement such dispensing in the form of drops. Generally, in order toform the delivered drops, the top portion of the dispensing head of thedevice has a shape of volume making it possible to define a drop.

SUMMARY OF THE INVENTION

An object of the present invention is to propose a device for dispensingpredetermined metered quantities of liquid while also improving thesterility of the dispensed liquid.

To this end, the invention provides a device for dispensingpredetermined metered quantities of liquid, which device includes asealing member that can take up a liquid release position, allowingliquid to flow out of the device, and a non-return position preventingliquid from flowing back into the device, wherein the sealing member isprovided with metering means for metering out the liquid to bedispensed.

Generally, the predetermined metered quantities of liquid are drops ofliquid. It should also be noted that the non-return or position isequivalent to a liquid-blocking position.

By means of this provision, the means for metering out the liquid areprovided directly by the sealing member, so that the liquid that isreleased by the sealing member in the release position, and that hasjust left the “sealed” zone of the device, is received directly in themetering means, without flowing through other parts. The risks of liquidpenetrating into other portions of the device after being released bythe sealing member are thus reduced. Indeed, when the metering means areprovided on a part other than the sealing member, e.g. the outer casingof the dispensing end-piece of the device, the liquid can penetrate intoother parts of the device while it is flowing between the sealing memberand the metering means. Such penetration of liquid into undesired zonesis a source of contamination, in particular through development ofbacteria. Otherwise, in order to avoid such a risk, it is necessary toprovide specific means for procuring sealing.

In addition, incorporating the metering means into the sealing membermakes it easier to reduce any “dead volume” that might containcontaminated liquid. Such dead volume corresponds to the volume situatedbetween the sealed zone (delimited in particular by the container and bythe sealing member) and the metering means for metering out the drops.Since the metering means are on the sealing member, they are closer tothe sealed zone, thereby keeping dead volume small. Furthermore, thesealing member can be made in such a manner that it fits as snugly aspossible against the parts so as to achieve a further reduction in thedead volume. In addition, since the sealing member is generally made inpart or entirely of a flexible material, it is easier to reduce thespaces so that it fits snugly against the parts than when the deadvolume is defined by rigid parts.

The invention may also have one or more of the followingcharacteristics.

The device includes bearing means for bearing against the sealingmember, in register with a recessed zone, serving to deform the sealingmember by bending deformation so that it takes up its non-returnposition.

The sealing member is flexible at least in part, and the device includesbearing means for bearing against the sealing member, serving to deformthe flexible portion of the sealing member by compression deformation sothat it takes up its non-return position. The flexible portion may bemade of an elastomer material or of a material sufficiently flexible forprocuring the sealing.

The metering means are means for forming drops of liquid.

The device includes a liquid-passing channel opening out into thedrop-forming means and the drop-forming means comprise a flared shapethat flares from said channel. This flared shape makes it possible toavoid jets of liquid being sprayed out.

The flared shape opens out into a substantially cylindrical shape. Thiscylindrical shape makes it possible to calibrate the drops that areformed.

The sealing member is an elastomer element that is made entirely ofelastomer. However, the member may also be implemented differently, inparticular by being made of a plastics material that is sufficientlyflexible.

The sealing member comprises an elastomer portion and a rigid portion,said portions being constrained to move with each other. The presence ofthe rigid portion makes it possible for said rigid portion to receiveany stresses exerted on the sealing member, while avoiding deforming theelastomer portion that thus procures sealing that is more constant overtime.

The metering means are formed in the rigid portion.

The portion of the sealing member that is provided with the meteringmeans is disposed in the immediate vicinity of an orifice for releasingliquid from the device.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention can be better understood on reading the followingdescription given merely by way of example, and with reference to theaccompanying drawings, in which:

FIG. 1 is a diagrammatic view showing how the sealing member of anembodiment of a device of the invention operates;

FIG. 2 is a view in longitudinal section showing an example of a deviceas shown diagrammatically in FIG. 1; and

FIG. 3 is a view analogous to FIG. 2, showing a variant of the exampleof FIG. 2.

DETAILED DESCRIPTION OF THE INVENTION

A liquid dispenser device comprises an end-piece 10, an example of whichis shown in FIGS. 2 and 3, designed to be mounted on a container made ofa plastics material and containing the liquid to be dispensed. Thedevice makes it possible to dispense predetermined metered quantities ofliquid, and more particular drops of liquid, for eye, nose, or mouthuse, e.g. drops of collyrium or eyewash for the eyes. The end-piece 10is mounted on a container 12, and more precisely on the neck 12 of thecontainer, said container being designed to be squeezed by the user forthe purpose of causing the liquid to flow out. In this example, thecontainer 12 is made of a plastics material and is designed to besqueezed by the user to cause the liquid to flow out. It is possible touse other types of container, in particular containers made of glass orof metal, it being possible for the user to release the liquid by actionother than by squeezing it, e.g. by pressing on an element foractivating a pump.

The end-piece 10 includes a sealing member 14 disposed between a firstportion 16 and a second portion 18 of the end-piece 10. Said sealingmember 14, or sealing valve, can take up a liquid-blocking position ornon-return or “check” position shown in FIGS. 2 and 3, in which positionit prevents any liquid from returning once said liquid has left thesealed zone, and a liquid release position (not shown). Preferably, themember 14 is disposed in the vicinity of the distal end of the end-piece10, in the vicinity of a liquid release orifice 64 (see FIG. 3). As canbe seen in the diagram of FIG. 1, the sealing member 14 is provided withmetering means 44 for metering out the liquid to be dispensed, whichmeans are described below.

The end-piece 10 is capped with a closure cap that is not shown in thefigures.

The configuration of the end-piece 10 in a particular embodiment isdescribed more precisely below, with reference to FIGS. 2 and 3. Theexample of FIG. 3 corresponds to a slight variant of the example of FIG.2. In FIG. 2, the sealing member 14 is in two portions 34, 36 and isheld in the blocking position by means of a return spring 15, whereas inFIG. 3, the member 14 is made entirely of an elastomer material and isheld in the blocking position by deformation, as described below.

As shown in FIG. 2, the first portion 16 of the end-piece 10 is an innercore 16 provided with a protuberance 19 that is of substantiallycylindrical shape and the projects from the distal end of the core 16.At its distal end, said protuberance 19 carries bearing means 20 forbearing against the sealing member 14. In this example, said bearingmeans 20 are composed of a projection forming an annular bead designedto bear against the sealing member 14. Alternatively, the bearing means20 may be composed of the end of the protuberance 19 only, withoutincluding a projection on said end. The inner core 16 is also providedwith a channel 22 for passing the liquid from the container towards theoutside of the device, and with a connection portion for connecting thecore 16 to the container 12. The end-piece 10 is also provided with ventmeans designed to pass air into the inside of the container so as tocompensate for the volume of liquid flowing out. In this example, thevent means are carried by the inner core 16 and they comprise a channel24 through which air can flow and across which a hydrophobic filter 26is disposed that is designed to filter the incoming air without,however, enabling liquid to escape via the channel 24. More precisely,in this example, the filter 26 is disposed in a housing 28 for receivingthe filter, which housing 28 is in the form of an annular groovedisposed at the center of the inside surface of the core 16, and inwhich groove the filter 26 is embedded.

In this example, the second portion 18 of the end-piece 10 correspondsto an outer top casing of the end-piece 10. This outer casing 18 isdesigned to cap the inner core 16, the sealing member 14 (at leastpartially), and the spring 15. More precisely, it is provided with anopen internal protuberance 30, formed by a central annular grooveopening out into the orifice 64, and designed to surround the distal endof the protuberance 18 and the distal end of the sealing member 14 insuch a manner as to make it possible for liquid to flow out of thedevice. The casing 18 is further provided with a bearing seat 32 for thereturn element 15, this seat 32 being disposed around the protuberance30. In this example, the distal end of the member 14, via which end theliquid is delivered, projects slightly from the orifice 64. Provisioncould be made for this end to come flush with the surface of the orifice64, or to be set back into the end-piece 10. Or else provision could bemade for the end 14 to project further from the surface of the casing18, thereby making it possible to isolate the drops more easily relativeto the surface of the casing 18.

In this example, the sealing member is made up of an elastomer portion34 and of a rigid portion 36, the portions 34 and 36 being constrainedto move with each other, i.e. when the portion 34 moves, the portion 36moves with it, and vice versa. In this example, the portions 34 and 36are assembled together by overmolding, but other types of assembly couldbe considered. The elastomer portion 34 is made of an elastomermaterial, such as silicone or a thermoplastic elastomer. The rigidportion 36 is made of a plastics material such as polypropylene. Therigid portion 36 is provided with a bearing surface 38 for the returnelement 15. As can be seen in the figures, the rigid portion 36 coversthe elastomer portion 34 over substantially the entire surface thereof,a zone 40 of the elastomer portion nevertheless being left free at theend of the elastomer portion, so as to enable said elastomer portion 34to lengthen. More precisely, each of the portions, namely the elastomerportion 34 and the rigid portion 36, has the shape of a hat providedwith a central cylindrical shape, of shape substantially complementaryto the shape of the protuberance 19 of the core 16, this cylindricalshape being extended at its proximal end by a brim. Thus, the rigidportion 36 covers the elastomer portion 34 over a large fraction of itssurface, except at its periphery 40. As can be seen in the figures, eachof the portions 34, 36 defines a channel 42, provided in the end-wall ofits cylindrical central shape, enabling the liquid to flow out. Inaddition, the sealing member 14 is provided with metering means 44, 46for metering out the liquid to be dispensed, these means being means forforming drops of liquid. More precisely, said means are formed in therigid portion 36 of the member 14. The means 44 have the shape of a conestarting from the channel 42 and flaring towards the distal end of thedevice, in such manner as to form a drop and to prevent the liquid beingdispensed in a jet, the cone 44 opening out into a cylindrical portion46 making it possible to calibrate the drop.

In this example, the return element 15 is a spiral metal spring. Thiselement 15 exerts a return force on the sealing member 14, by bearing onthe surface 38 of the rigid portion 36, in such a manner as to urge thesealing member 14 back into its liquid-blocking position.

As can be seen in the figures, the sealing member 14 is fastened betweenthe two portions 16, 18 in leaktight manner, in order to prevent anyliquid flowing through the channel 22 from escaping into the casing 18.

Operation of the dispenser device of FIG. 2 is described below.

When the user wishes to use the device, said user firstly removes thecap from the device. In order to dispense drops of liquid, the useractuates the device, thereby increasing the pressure inside thecontainer, and causing liquid to flow into the channel 22, and therebyexerting pressure on the elastomer portion 34. Under this pressure, thesealing member goes from its liquid-blocking position to its liquidrelease position, by moving in translation upwards, as indicated by thearrow 48. More precisely, the zone 40 of the elastomer portion 34deforms, by lengthening, so as to allow the elastomer portion to moveupwards in this way. At the end of this movement, the sealing providedby the bearing means 20 co-operating with the sealing member 14 isbroken, and the liquid can flow through the channel 42 and into theportions 44, 46, so as to form a drop of liquid. The path of the liquidis indicated by the arrow 50. Once the drop has been released, the usercan cease to exert pressure on the container, which fills with air viathe channel 24. In addition, since the pressure from the outgoing liquidceases, the sealing member 14 resumes its liquid-blocking position,under the effect of the return force of the element 15. Thus, thebearing means 20 and the elastomer portion of the member 14 co-operateagain so as to prevent liquid from flowing out. It should be noted that,in this blocking position, the member 14 blocks the liquid bycompression of the portion 34 against the rigid portion 36, thiscompression being achieved by the means 20.

It should be noted that the example described can have variants. Inparticular, the return element 15 is a spiral spring, but it is possibleto provide other types of return spring, made of metal or of some othermaterial, such as a resilient blade or an elastomer element. Inparticular, said return element 15 may be incorporated directly into thesealing member 14 by being incorporated either into the elastomerportion 34 or into the rigid portion 36, or else it may be incorporatedinto the casing 18.

Among the advantages of the device of FIG. 2, it can be understood that,since the metering means 44, 46 are provided on the member 14, they areno longer close to the sealed zone, defined by the bearing of the means20. In addition, since said metering means are disposed directly on themember 14, the risks of contamination by the liquid penetrating into the“dirty” portions (disposed downstream from the sealed zone) are muchlower than if said metering means were disposed on a part that is notsecured to or integral with the member 14, e.g. on the casing 18. Itshould be noted that, in the example of FIG. 2, the metering means areprovided on the rigid portion 36, and this can be easier to implementand can procure more uniform metering than if they were provided on theelastomer portion 34. However, it is also possible to consider providingthem on said elastomer portion 34.

Among the other advantages of the dispenser device in this example, itshould be noted, in particular, that the rigid portion 36 constitutes asort of shell for the elastomer portion 34, which shell makes it easierto exert stress on the sealing member 14, without any risk of deformingit.

In the variant of FIG. 3, the sealing member is an element that may bemade of elastomer or of a plastics material that is sufficientlyflexible, and that is made entirely of the same material, and theend-piece does not include any spring. In this example, the member 14achieves the liquid-blocking by being mounted as deformed on the device.The member 14 is hat-shaped, provided with a cylindrical shape 65 andwith a brim 66. The periphery 68 of this brim is fastened permanentlybetween the portions 16 and 18, so as to provide static sealing. Thisfastening is achieved by deforming the member 14: said member 14 isfitted over the protuberance 19 and deformed in such a manner that themember 14 is constrained to press against the protuberance 19, and moreprecisely against the means 20. The shape of the member 14 shown in FIG.3 is different from the shape of the member 14 prior to assembly. Thispressing of the member 14 procures the sealing in the blocking position.Thus, in this example shown in FIG. 3, the member 14 blocks the liquidby bending deformation of the member 14, procured by the bearing means20 disposed in register with a recessed zone.

In the example shown in FIG. 3, the metering means 44, 46 are providedentirely in the elastomer element 14. These means 44, 46 are analogousto the means of FIG. 2.

The device of FIG. 3 operates analogously to the device of FIG. 2.

It should be noted that the invention is not limited to theabove-described examples.

1. A device for dispensing predetermined metered quantities of liquid,which device includes a sealing member that can take up a liquid releaseposition, allowing liquid to flow out of the device, and a non-returnposition preventing liquid from flowing back into the device, whereinthe sealing member is provided with metering means for metering out theliquid to be dispensed, the metering means being means for forming dropsof liquid, the device including a liquid-passing channel opening outinto the drop-forming means and the drop-forming means comprising aflared shape that flares from said channel.
 2. A device according toclaim 1, including bearing means for bearing against the sealing member,in register with a recessed zone, serving to deform the sealing memberby bending deformation so that it takes up its non-return position.
 3. Adevice according to claim 1, wherein the sealing member is flexible atleast in part, and the device includes bearing means for bearing againstthe sealing member, serving to deform the flexible portion of thesealing member by compression deformation so that it takes up itsnon-return position.
 4. A device according to claim 1, wherein theflared shape opens out into a substantially cylindrical shape.
 5. Adevice according to claim 1, wherein the sealing member is an elastomerelement that is made entirely of elastomer.
 6. A device according toclaim 1, wherein the sealing member comprises an elastomer portion and arigid portion, said portions being constrained to move with each other.7. A device according to claim 6, wherein the metering means are formedin the rigid portion.
 8. A device according to claim 1, wherein theportion of the sealing member that is provided with the metering meansis disposed in the immediate vicinity of an orifice for releasing liquidfrom the device.